Method and apparatus for accessing higher privileged functions from lower privileged functions

Patent metadata

Field	Value
Publication number	US-9986271-B2
Application number	US-201514819789-A
Country	US
Kind code	B2
Filing date	Aug 6, 2015
Priority date	Apr 3, 2002
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

The invention provides a method and apparatus that addresses and resolves the issues currently affecting the ability to offer Enhanced TV, in particular, those issues concerning timing and synchronization, interaction with other modules in the STB, and distribution.

First claim

What is claimed is:

1. A method comprising:
receiving, by a computing device storing a first application, a first data stream comprising a second application, wherein a function of the first application has a first privilege level and the second application has a second privilege level lower than the first privilege level;
reducing, by the first application executing on the computing device, the first privilege level of the function to a third privilege level;
sending, by the first application executing on the computing device and to the second application, a notification of an availability of the function and an indication of the third privilege level; and
in response to determining that the second privilege level of the second application is at least equal to the third privilege level, permitting the second application to use the function of the first application.

2. The method of claim 1 , wherein the permitting comprises executing a thread associated with the second application at the first privilege level.

3. The method of claim 2 , further comprising preventing the thread from being aborted by an error associated with a callback invoked by the first application.

4. The method of claim 1 , further comprising:
receiving, by the first application and from the second application, a call at the second privilege level to use the function;
wherein the permitting comprises:
executing the call at the first privilege level; and
sending, by the first application and to the second application, a call to invoke a callback at the second privilege level.

5. The method of claim 4 , further comprising preventing the callback from executing at the first privilege level.

6. The method of claim 1 , further comprising executing the second application at the second privilege level.

7. The method of claim 1 , wherein the permitting is performed without using an access control list.

8. The method of claim 1 , wherein the notification comprises a name of the function of the first application and a publication name for use by the second application.

9. A method comprising:
receiving, by a computing device storing a first application, a first data stream comprising a second application, wherein a function of the first application has a first privilege level and the second application has a second privilege level lower than the first privilege level;
reducing, by the first application executing on the computing device, the first privilege level of the function to a third privilege level;
sending, by the first application executing on the computing device and to the second application, a notification that the function of the first application is available for use by the second application and an indication of the third privilege level; and
in response to determining that the second privilege level of the second application is at least equal to the third privilege level, executing a thread associated with the second application to use the function of the first application at the first privilege level.

10. The method of claim 9 , further comprising preventing the thread from being aborted by an error associated with a callback invoked by the first application.

11. The method of claim 9 , further comprising:
receiving, by the first application and from the second application, a call at the third second privilege level to use the function;
executing the call at the first privilege level; and
sending, by the first application and to the second application, a call to invoke a callback at the second privilege level.

12. The method of claim 11 , further comprising preventing the callback from executing at the first privilege level.

13. The method of claim 9 , further comprising executing the second application at the second privilege level.

14. The method of claim 9 , wherein the executing is performed without using an access control list.

15. The method of claim 9 , wherein the notification comprises a name of the function of the first application and a publication name for use by the second application.

16. A method comprising:
receiving, by a computing device storing a first application, a first data stream comprising a second application, wherein a function of the first application has a first privilege level and the second application has a second privilege level lower than the first privilege level;
reducing, by the first application executing on the computing device, the first privilege level of the function to a third privilege level;
sending, by the first application executing on the computing device and to the second application, a notification that the function of the first application is available for use by the second application and an indication of the third privilege level;
in response to determining that the second privilege level of the second application is at least equal to the third privilege level,
executing a first call to the function from the second application at the first privilege level; and
receiving, by the second application and from the first application, a second call to invoke a callback at the second privilege level.

17. The method of claim 16 , wherein the first call corresponds to a thread associated with the second application, the method further comprising:
preventing the thread from being aborted by an error associated with the callback.

18. The method of claim 16 , wherein the executing is performed without using an access control list.

19. The method of claim 16 , wherein the notification comprises a name of the function of the first application and a publication name for use by the second application.

Assignees

• Comcast Cable Communications Man Llc

Inventors

• Bulkowski Brian
• Wales Carolyn
• Hsu Sam
• Helman James
• Decker Joseph
• Wagenaar Brock
• Vickers Mark

Classifications

• H04N21/654

  Transmission by server directed to the client · CPC title

• H04N21/4385

  Multiplex stream processing, e.g. multiplex stream decrypting · CPC title

• H04N21/23602

  Multiplexing isochronously with the video sync, e.g. according to bit-parallel or bit-serial interface formats, as SDI · CPC title

• H04L25/14

  Channel dividing arrangements {, i.e. in which a single bit stream is divided between several baseband channels and reassembled at the receiver} · CPC title

• H04J3/0685

  Clock or time synchronisation in a node; Intranode synchronisation · CPC title